Most TPMS are accurate enough for pressure for normal tire maintenance and serve a purpose beyond warning you of impending problems. One should know that their tires are properly inflated at 70 deg as recommended by the tire manufacturer. You can check the tires with a quality pressure gauge or TPMS. I prefer the TPMS since I have one. Therefore when one starts their journey they should know if the tires are properly inflated. As far a IR guns are concerned, they are the gold standard that most people like race car pit crews use to determine tire temps. I agree about calling the manufacturer about technical details and concerns.